Important - check this every time you set up

There's a phenomenon I call a Reflected Hot-Skin condition where a Hot-Skin voltage on one RV in a campground can "Reflect" to others in the same loop. But that can only occur if the campground pedestals have an incorrect ground to begin with.

Here's how it works.... Imagine you you have pedestals hooked up on a common feed from the campground's service panel. This is called a "daisy chain" connection. There will be common hot1, hot2, neutral, and ground wires interconnecting all these pedestals. Since the "ground" wire is supposed to be bonded to the service panels Ground-Neutral-Earth connection, any hot-to-chassis current leakage or short inside of a single RV can only go to this "ground" where it will be drained away or trip the RV's circuit breaker. That's exactly how it's all supposed to work. In a properly grounded system it's impossible for any chassis to develop more than a volt or two potential above earth-ground, no matter what kind of other failure occurs.

Now assume there's a break in this pedestal ground wiring on its way back to the service panel's Ground (G-N-E bonding point). Now if one of the RVs develops a short between line-and-chassis the current will have no path to "ground" and it will electrify the entire ground wire interconnecting all the pedestals and RVs together. So anything with a ground wire plugged into one of these pedestals will have its chassis electrified to 120 volts, creating a Hot-Skin condition.

The really dangerous thing about this mis-wiring condition is that because the voltage is feeding into your RV from the ground wire, even shutting off the pedestal or RV circuit breaker can't stop it. And there's no EMS products on the market that can disconnect you from this hot-ground since electrical code does not allow the manufacturer to put a relay contact in the path of the ground wire (officially called the EGC for Equipment Grounding Conductor). However, the EMS will detect the hot-ground condition and shut off your RV's live voltage. So it will appear that you have no AC power from your EMS, while in reality your RV's ground is the only thing electrified.

I've only heard of perhaps half a dozen campgrounds with this non-grounded EGC problem, which allowed a Reflected Hot Skin Condition to occur. While this is a very rare problem, it's still something to be aware of and can easily be detected with a NCVT at any time. If you ever feel a tingle, stop what you're doing and immediately test for a hot-skin voltage. If you do measure one, disconnect from shore power until the problem is resolved.

Originally posted by jmsokol There's a phenomenon I call a Reflected Hot-Skin condition where a Hot-Skin voltage on one RV in a campground can "Reflect" to others in the same loop. But that can only occur if the campground pedestals have an incorrect ground to begin with. Here's how it works.... Imagine you you have pedestals hooked up on a common feed from the campground's service panel. This is called a "daisy chain" connection. There will be common hot1, hot2, neutral, and ground wires interconnecting all these pedestals. Since the "ground" wire is supposed to be bonded to the service panels Ground-Neutral-Earth connection, any hot-to-chassis current leakage or short inside of a single RV can only go to this "ground" where it will be drained away or trip the RV's circuit breaker. That's exactly how it's all supposed to work. In a properly grounded system it's impossible for any chassis to develop more than a volt or two potential above earth-ground, no matter what kind of other failure occurs. Now assume there's a break in this pedestal ground wiring on its way back to the service panel's Ground (G-N-E bonding point). Now if one of the RVs develops a short between line-and-chassis the current will have no path to "ground" and it will electrify the entire ground wire interconnecting all the pedestals and RVs together. So anything with a ground wire plugged into one of these pedestals will have its chassis electrified to 120 volts, creating a Hot-Skin condition. The really dangerous thing about this mis-wiring condition is that because the voltage is feeding into your RV from the ground wire, even shutting off the pedestal or RV circuit breaker can't stop it. And there's no EMS products on the market that can disconnect you from this hot-ground since electrical code does not allow the manufacturer to put a relay contact in the path of the ground wire (officially called the EGC for Equipment Grounding Conductor). However, the EMS will detect the hot-ground condition and shut off your RV's live voltage. So it will appear that you have no AC power from your EMS, while in reality your RV's ground is the only thing electrified. I've only heard of perhaps half a dozen campgrounds with this non-grounded EGC problem, which allowed a Reflected Hot Skin Condition to occur. While this is a very rare problem, it's still something to be aware of and can easily be detected with a NCVT at any time. If you ever feel a tingle, stop what you're doing and immediately test for a hot-skin voltage. If you do measure one, disconnect from shore power until the problem is resolved.

Originally posted by jmsokol Originally posted by Rustler Thant's an interesting situation, Jim. So I'll need to be watchful. For that condition I suppose one of those 3 light testers would show if the campground had an open ground. Also something like the progressive Industries EMSHW30C would have detected the open ground situation and have disconnected. I wonder if an RV with reverse polarity bootleg ground (RPBG) wired outlet can affect other RVs connected to the same campground. It seems that the CG's properly wired ground would cause the faulty RV's hot ground line to trip a breaker somewhere. But maybe not since the ground line doesn't have a breaker on it. Yet the faulty RV had better have a circuit breaker on its hot line, which is now connected to CG's ground. So a related question is this: Can a single RPBG-wired outlet affect other properly wired outlets within the same RV or other RVs connected via a campground electrical system? Actually my name is Mike not Jim. The JM in JMSOKOL is for John Michael, which only grade school nuns and cops call me. Hah! To answer your question, an RPBG in an RV CANNOT cause hot skin voltage in any other RVs in a campground as long as the campground wiring is properly grounded. In the case of an open ground path to the service panel Neutral-Ground bond, a 3-light tester will indicate an open ground, but it won't tell you the ground is Hot. Mike Sokol

Originally posted by Rustler Thanks, Mike. So to wrap my brain around the issue is this the recommended procedure? Use a 3-light tester to detect open ground (or other issues) at home or campground outlet. Use NCVT to check outlet terminals for correct wiring. Use something like a Progressive Industries EMSHW30C to detect and protect against other hazardous conditions.  Is item 1 unnecessary if 2 and 3 are employed? If a single outlet is wired with RPBG, but other outlets are wired correctly (say at home or in an RV), could that situation go undetected without a circuit breaker tripping? Thanks so much for your patience in helping those of us a bit electrically challenged!

I would still use a 3-light tester as the first check of the outlet. If it won't pass that simple test, then don't plug in. Then use an NCVT to detect a hot-ground from a RPBG. And having a EMS in the circuit will protect you from over-voltage conditions. After plugging in your RV's shore power line, do a final test with a NCVT to confirm that you don't have a break in the EGC ground conductor of any extension cords of internal chassis-ground bonds inside your RV. This entire test sequence should only take a minute or two at most.

Mike Sokol

I read this thread thread the day all 16 pages.Today I was called out to put a50 amp outlet in for a food truck job went fine did the rcvt test no problems then I went inside to talk to the owner since I had rcvt in hand I ran it over metal in the truck and found the outside of the icebox was hot. It came down to a home made extension cord. If not for this thread I would never thought of this. Thanks guy.the owner of the thanks you to